Boeing doesn't know what's failing with the thrusters. They haven't been able to give NASA a root cause so even though they got 4 of the 5 anomalous thrusters working again, who knows what could fail on the return flight.

Boeing should bail and NASA will grumble at the sunk cost of their failed pursuit of redundancy but everyone will be better off.

When the ISS had at least 10 years left, paying the increasing costs for Boeing's failures might have been worth it. With only about 5 years left now for crew transport, SpaceX can build one or two more Crew Dragons and cover the load with a vehicle that's well-proved and far less costly than Starliner.

If Boeing is forced to re-do this test, if NASA calls CFT a failure and Boeing has to eat the cost of re-doing it, I think Boeing bails. The 5 flights they might still get paid for wouldn't be worth it after the cost of another test.

If NASA has the astronauts return on Dragon, Starliner is cooked regardless of what Boeing wants and Boeing wears that black eye for NASA and even some of its DOD supporters.

I think Boeing wants out and NASA's trying to hold onto them. This test isn't about Starliner so much as it is about how NASA and Boeing wind down this program.